Computer communications systems are a collection of computer systems that communicate via a network. Specifically, for any particular communication, one computer system is a sending system while another computer system is a receiving system. In other words, the sending system sends the message to the receiving system. On the receiving system, when a new message is received, the receiving system sends an interrupt to the application executing on the receiving system to which the message is directed. The interrupt notifies the application that the new message is received and is ready to be processed. If the single message includes multiple packets, then the interrupt is sent after the last packet of the message.